Forest fragmentation in the temperate zone and its effects on migratory songbirds

Abstract

SummaryAlthough much attention has been paid to the impacts of tropical deforestation on populations of Neotropical migrants, fragmentation of breeding habitat may be an equally serious problem for many of these birds. Populations of many migrant songbirds have been declining in recent decades, especially within small woodlots. Censuses from woodlots of different sizes also consistently show that many migrant songbirds are area-sensitive, i.e. they are absent from all but the largest woodlots in a region. In contrast, long-term censuses from large, unfragmented forests show few consistent patterns of decline in Neotropical migrants. Population declines are therefore linked to forest fragmentation because they are most pronounced in small, isolated woodlots.